Chain Reactions and Nuclear Reactors

Abstract

Release of significant amounts of energy from nuclear fission requires a chain reaction. For the buildup of a chain reaction, each generation must have more fission events than the preceding one. This means that the average number of neutrons produced in a fission event must be significantly greater than unity. This excess is necessary because some neutrons will be lost, instead of inducing fission in the next generation. For example, some neutrons will be lost to capture reactions, and others will exit the region in which the chain reaction is to be established.